The present invention relates to a peritoneal dialysis apparatus using a disposable cassette (peritoneal dialysis circuit) integrally formed with a diaphragm and heating portion.
The recent dialysis process employing peritoneal dialysis has been attracting attention because the cost of treatment is less expensive than with the dialysis process employing an artificial kidney and peritoneal adhesion can be prevented.
According to a peritoneal dialysis apparatus used in the dialysis process employing peritoneal dialysis, generally, a fluid infusing bag connected to a dialysis fluid container (bag) containing a peritoneal dialysis fluid (to be referred to as a dialysis fluid hereinafter) to be infused or delivered to inside the patient""s peritoneum (peritoneal cavity) and a reservoir bag connected to a drained fluid container (bag) for recovering the dialysis fluid drained from the patient are placed in a pressure chamber and are used. More specifically, the pressure chamber for accommodating the fluid infusing bag and reservoir bag is formed in the dialysis apparatus body of the peritoneal dialysis apparatus. When the pressure in the pressure chamber is increased or decreased, the fluid infusing bag or reservoir bag pumps. The dialysis apparatus body has a heater for heating the dialysis fluid in the fluid infusing bag to a temperature within a predetermined temperature range.
In the conventional peritoneal dialysis apparatus, the chamber and heater must have sizes corresponding to the fluid infusing bag and reservoir bag, and the peritoneal dialysis apparatus itself becomes large in size as well as in weight. For this reason, in the site of medial treatment, particularly in home medical treatment, a large space for the peritoneal dialysis apparatus is needed in the house, and handling such as transportation of the peritoneal dialysis apparatus becomes cumbersome to interfere with a smooth medical care.
Japanese Patent No. 3113887 proposes a peritoneal dialysis apparatus in which when selecting the flow path of the disposable cassette, it can be switched by opening/closing a valve with a valve actuator. Japanese Patent Laid-Open No. 11-347115 proposes a disposable cassette integrally having a heating portion and a pump (diaphragm) for distributing a peritoneal dialysis fluid. This cassette is heated from the two sides, and the heated peritoneal dialysis fluid is distributed into the patient""s peritoneal cavity with two pumps (diaphragms).
With the former apparatus, since the valve actuator is operated intermittently, the working noise of the valve is generated in the nighttime dialysis while the patient is a sleep, which offends his or her ears.
With the latter apparatus, the heating ability is not sufficient with respect to the fluid distributing ability of the pump.
The continuous ambulatory peritoneal dialysis (to be also referred to as xe2x80x9cCAPDxe2x80x9d hereinafter) has been attracting great attention because with which the patient himself or herself can exchange the dialysis fluid container (bag) at home or in the office, allowing him to lead normal life.
According to the CAPD, a catheter tube (peritoneal catheter) is placed in the patient""s peritoneal cavity. A transfer tube is connected to the end of the catheter tube outside the body. A bag tube for a dialysis fluid bag (fluid infusing bag) containing a dialysis fluid is connected to the transfer tube. The dialysis fluid in the bag is infused into the peritoneal cavity through the respective tubes, and dialysis is performed for a predetermined period of time. After that, the spent dialysis fluid in the peritoneal cavity is recovered in a drained fluid bag through the respective tubes. Two tubes are connected to each other in an aseptic condition by fitting the male and female connectors mounted on their ends.
In the CAPD, the dialysis fluid is infused to inside the peritoneum by placing the dialysis fluid bag at a position higher than the patient""s abdomen by about 1 m and transferring the dialysis fluid from the dialysis fluid bag into the abdomen inside the peritoneum under the gravity. The spent dialysis fluid from inside the peritoneum is recovered by placing the drained fluid bag at a position lower than the patient""s abdomen by about 1 m and transferring the dialysis fluid from inside the peritoneum to the drained fluid bag under the gravity.
According to this dialysis fluid infusing and draining method, when peritoneal dialysis is to be performed while the patient sleeps, the patient must be laid at a position higher than the floor by about 70 cm to 100 cm by using a bed, and the dialysis fluid bag must be set at a position higher than the patient by about 1 m. As a result, the height of the entire apparatus becomes as large as about 2 m. Then, the apparatus is difficult to handle and transport. Moreover, if the patient turns over during sleeping, the apparatus might fall. Since a gravity necessary for draining the fluid must be maintained, the patient""s sleeping position (height) cannot be freely selected.
In order to make up these drawbacks, a peritoneal dialysis apparatus has been proposed in which fluid infusion and draining are automated and the heights of the positions to set the dialysis fluid bag and drained fluid bag are not limited. For example, Japanese Patent No. 3113887 proposes a peritoneal dialysis apparatus in which when selecting the flow path of the disposable cassette, it can be switched by opening/closing a valve with a valve actuator. Japanese Patent Laid-Open No. 11-347115 proposes a disposable cassette integrally having a heating portion and a pump (diaphragm) for distributing a peritoneal-dialysis fluid. This cassette is heated from the two sides, and the heated peritoneal dialysis fluid is distributed into the patient""s peritoneal cavity with two pumps (diaphragms).
However, in order to perform peritoneal dialysis at home by using such a peritoneal dialysis apparatus, the patient must be sufficiently trained so he can utilize the peritoneal dialysis apparatus, must memorize all the procedures by himself, and must operate the peritoneal dialysis apparatus correctly. This is no small burden to the patient.
If a minor trouble should occur in the operation procedures, he may not be able to cope with it immediately.
The present invention has been made in consideration of the above problems, and has as its object to provide a compact, lightweight peritoneal dialysis apparatus using a disposable cassette integrally formed with a diaphragm and heating portion, in which the flow path can be switched quietly and the heating ability is high.
In addition, it is another object of the present invention to provide a peritoneal dialysis apparatus in which a detachable cassette can be loaded reliably and easily by anyone while a sufficiently high heating ability is maintained.
It is still another object of the present invention to provide a peritoneal dialysis apparatus with which automatic dialysis treatment can be performed by the patient himself and the operation procedures of which are very clear and easy to understand, so dialysis treatment can be performed with optimal conditions.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.